Hello Fellows,

I'm starting to try and track down a smoke issue with the truck. Tonight I ran compression test on it with a (Cold) engine. I did notice, when I was checking cylinder huber #5 about thirty seconds to one minute after cranking the engine I could hear a gurgling sound from inside the engine. I know I'm not going to see the gauge drop in pressure because of the schraeder valve will hold line pressure but I don't remember hearing the gurgling sound before when doing a compression testing. All cylinders had 350 PSI. on them except #2 and #4. Both of them are around 250 PSI. I'm going to look into them some more but the gurgling sound has me a bit puzzled.

Have you guys experienced anything like this when doing a compression check?

 

It may be a injector oring

 

Snakedoc,

Thanks for the reply.

I had thought about that too. I need to go back and make sure it was only doing it on that cylinder. By the time I got done for the evening, I couldn't remember if that was the case. I really hate it when I don't keep better notes.

Thanks

 

250? Hope it's O-rings. I'd replace O-rings/copper washers and pushrods in #2 and #4 and try again. If it doesn't come up with the others, that engine may be done.

 

Thanks for the input Rich.

I was already thinking the injector o-rings but hadn't thought about push rods.

Any ideas on where I can find a procedure for changing push rods?

I haven't bought the Ford manuals yet because I'm not exactly sure which ones to get.

 

That one's easy-peasy. Pull two rocker arm bolts, pull old pushrod, reverse procedure. I think the torque on the rocker arm bolt is 120 inch pounds, but that needs to be verified.

 

Rich....what would the pushrods have to do with this?

 

A bent pushrod will have nothing to do with low compression. A bent valve will have an effect on compression.

 

Dan, i tried but alas... still repcuffed...

Rich...
Stop calling motors with low compression done.
They are not done...
They are opportunities for greatness!

X3 what the last two stated...

Rings
Holes in pistons
Or bent/unseated valves.

Pushrods have ***** all to do with compression loss except for in the event some are installed that are too long... pretty much zero chance of that on a factory motor.

250psi is actually a good sign for salvaging the block.
My guess is broken top rings and a little scoring.

If you dont rebuild it maybe we can work something out?

I kinda wanna start lining them up in the shop like Rockettes!

 

Thanks for the replays guys.

Even though #4 and #6 have low compression right now, I'm not total convinced yet that the block needs to be rebuilt. I need to get a better look at it. The engine only has 165K on it and in by no means has it been hot rodded. No chips or major mods of any kind. For the most part the oil has always been changed at 3 to 5k.

If anyone has any other ideas of what to look at please speak up. I'm wanting to look at everything and anything while I'm in there.

Thanks,

Brice

 

I'm not saying the pushrods can fix the truck, it's just a very inexpensive thing to do to eliminate any easy possibilities - and it affords the opportunity for more inspection. I guess I should clarify my version of "done". A windowed block is a "dead" engine, an engine with low compression is "done" with all it can do without pulling it.

If the pushrod experiment is a fail, he's still going to need them for a rebuild anyway. If he trades for a long block, he's out a few bucks for the two pushrods.

 

that gauge should peg its compression #'s within seconds, not 1/2 - 1 minute. Hoping you find it to be an easy fix/replacement part

 

Rich...why would he need need pushrods for a rebuild? Unless, of course he either, a) has some bent ones, or b) wants to increase the seat pressure of the valves which may require a heavier wall pushrod.

 

Hey Guys,

At this pointing, I'm trying to do everything I can not to have to do a rebuild. I want to rule out every possibility I can for this low compression issue.

I'm kinda stumped right now with it though. Let me reiterate this engine only has 165K on it. It's not hot rodded or anything. No chips etc. I would not say it is pushed hard at all.

I just replaced all Injk. O-rings and copper washers on drivers side with no change.
I pulled the push rods on the #4 cylinder. There doesn't appear to be a bend in either one of the push rods. I even rolled them on them on a flat surface and it doesn't appear there is an issue.

I'm thinking now, I need to remove the valve springs and check the valve stems and see if they are bent (as much as I can anyway). After that I don't know what else I can check. The only other thing would be the lifters but I don't think they can be removed with the head on unless I'm missed informed.

If you guys have any ideas let me know,

Thanks,
Brice

 

I might have a "hangover" from my gasser experience or my chain-and-sprocket experience, but I'm thinking new lifters and pushrods with a rebuild. The theory is the new lifters with the old pushrods could accelerate wear at the contact point until the faces match. I don't know if metal fatigue is even a factor, but these diesels are supposed to go a helluva lot farther between rebuilds than gassers - and the pushrods are inexpensive. I'd just do it... me being me and all.

The lifters are waaay down in the guts under the head. I looked at them with an inspection camera and I seem to recall they are not accessible without lifting the head.